The present invention generally relates to the field of nanotechnology and drilling fluids. More particularly, the present invention relates to nanoparticle smart tags and the use of nanoparticle smart tags in the detection of chemical species.
Drilling is a crucial process for recovering economically important materials found in subterranean environments. For example, drilling may be used to recover oil, precious metals, water, and other natural resources. Because of the large expenses involved in subterranean explorations, it is often important to quickly determine the commercial viability of a wellbore. For mineral exploration, a detection scheme may be used to determine whether an ore contains sufficiently high concentrations of minerals. In the case of groundwater drilling, a detection scheme can provide a careful analysis of the chemical compositions present in groundwater, checking for possible contaminants to fresh water sources.
Detection schemes typically require the use of tags which interact with the chemical species of interest (i.e., an analyte), which in turn can be analyzed by a number of analytical techniques. As used herein, a “tag” refers to a composition that aids in the detection of an analyte. In a typical analytical setup, the physical (e.g., temperature, concentration, location, etc.) and/or chemical (e.g., reactivity, toxicity, oxidation state, etc.) properties of an analyte may be measured directly or indirectly wherein the analyte's interaction with a tag alters a measurable property of the analyte, tag, or both. The interaction between the tag and the analyte may be via electrostatic interaction, chemical bond, adsorption (physical or chemical), etc. Examples of tags include, but are not limited to, organic dyes, fluorescent antibodies, radioisotopes, and nanoparticles.
Analytical tools such as spectroscopy are generally used in a detection scheme to detect the chemical species once the interaction has occurred. The challenge for current detection scheme, is to be able to detect low amounts of analyte in a chemically complex environment. Another limitation of current detection schemes is the amount of time required to analyze the chemical composition present in a given wellbore. In a typical setup, samples need to be collected, time stamped, sent to a remote site for analysis, and then analyzed. It is not uncommon for this process to take several days, if not weeks.